J Clin Gynecol Obstet

Journal of Clinical Gynecology and Obstetrics, ISSN 1927-1271 print, 1927-128X online, Open Access

Article copyright, the authors; Journal compilation copyright, J Clin Gynecol Obstet and Elmer Press Inc

Journal website http://www.jcgo.org

Original Article

Volume 4, Number 2, June 2015, pages 203-208

Predictors of Prenatal Screening for Fragile X Syndrome

**Table 1.** Fragile X Results by Family History
	Family history of fragile X (N = 222)	No history of fragile X (N = 5,268)
Not tested	149	67.1	4,392	83.4
Normal	72	32.4	852	16.2
Intermediate	0	0	20	0.4
Premutation	1	0.5	4	0.08
Full mutation	0	0	0	0

Table 1. Fragile X Results by Family History

Family history of fragile X (N = 222)

No history of fragile X (N = 5,268)

Not tested

149

67.1

4,392

83.4

Normal

32.4

852

16.2

Intermediate

0.4

Premutation

0.5

0.08

Full mutation

**Table 2.** Unadjusted and Adjusted Predictors of Fragile X Carrier Screening
	Not tested (N = 4,541) (%)	Tested (N = 949) (%)	Unadjusted OR (95% CI)	P-value	Adjusted aOR* (95% CI)	P-value
*Controlled for all predictors and covariates.
Gestational age at visit
< 16 weeks	3,715 (81.8)	799 (84.2)	1.18 (0.98 - 1.43)	0.08	1.53 (1.21 - 1.95)	< 0.001
≥ 16 weeks	826 (18.2)	150 (15.8)	Reference		Reference
Insurance type
Medical/Medicaid	1,145 (25.3)	317 (33.5)	1.49 (1.28 - 1.73)	< 0.001	1.96 (1.61 - 2.39)	< 0.001
Private	3,382 (74.7)	630 (66.5)	Reference		Reference
Family history
Fragile X	149 (3.3)	73 (7.7)	2.90 (2.17 - 3.89)	< 0.001	2.06 (1.48 - 2.86)	< 0.001
Inheritable	231 (5.1)	79 (8.3)	2.03 (1.55 - 2.65)	< 0.001	1.44 (1.06 - 1.96)	0.02
Multifactorial	381 (8.4)	159 (16.8)	2.47 (2.02 - 3.03)	< 0.001	1.88 (1.47 - 2.40)	< 0.001
Non-contributory	3,780 (83.2)	638 (67.2)	Reference		Reference
Counselor
1	409 (9.2)	210 (22.2)	14.04 (9.60 - 20.54)	< 0.001	12.63 (8.54 - 18.67)	< 0.001
2	1,064 (23.8)	323 (34.1)	8.30 (5.77 - 11.95)	< 0.001	7.88 (5.42 - 11.47)	< 0.001
3	403 (9.0)	98 (10.3)	6.65 (4.43 - 9.99)	< 0.001	5.62 (3.69 - 8.56)	< 0.001
4	349 (7.8)	76 (8.0)	5.96 (3.90 - 9.09)	< 0.001	5.48 (3.55 - 8.48)	< 0.001
5	404 (9.1)	73 (7.7)	4.94 (3.24 - 7.55)	< 0.001	4.55 (2.94 - 7.05)	< 0.001
6	808 (18.1)	120 (12.7)	4.06 (2.74 - 6.01)	< 0.001	3.48 (2.32 - 5.22)	< 0.001
7	95 (2.1)	13 (1.4)	3.74 (1.91 - 7.34)	< 0.001	3.46 (1.72 - 6.97)	< 0.001
8	930 (20.8)	34 (3.6)	Reference		Reference
Counseling time
≥ 60 min	1,071 (23.6)	325 (34.2)	2.24 (1.89 - 2.66)	< 0.001	2.87 (2.04 - 4.02)	< 0.001
> 30 - 60 min	781 (17.2)	251 (26.4)	2.37 (1.97 - 2.85)	< 0.001	2.55 (1.80 - 3.61)	< 0.001
> 5 - 30 min	363 (8.0)	58 (6.1)	1.18 (0.87 - 1.59)	0.28	1.66 (1.10 - 2.52)	0.02
≤ 5 min	2,326 (51.2)	315 (33.2)	Reference		Reference
Invasive procedure
Yes	431 (9.5)	218 (23.0)	2.84 (2.37 - 3.41)	< 0.001	2.46 (1.98 - 3.06)	< 0.001
No	4,110 (90.5)	731 (77.0)	Reference		Reference
Maternal age
≥ 35 years	1,542 (34.0)	441 (46.5)	1.69 (1.47 - 1.95)	< 0.001	0.97 (0.75 - 1.25)	0.83
< 35 years	2,999 (66.0)	508 (53.5)	Reference		Reference
Ethnicity/ancestry
Ashkenazi Jewish	137 (3.0)	59 (6.2)	2.23 (1.62 - 3.08)	< 0.001	1.38 (0.96 - 1.97)	0.08
African American	297 (6.5)	57 (6.0)	0.99 (0.73 - 1.35)	0.97	0.95 (0.68 - 1.32)	0.75
Asian	762 (16.8)	160 (16.9)	1.09 (0.89 - 1.33)	0.41	1.07 (0.86 - 1.34)	0.53
Asian Indian	128 (2.8)	33 (3.5)	1.34 (0.90 - 1.99)	0.15	1.48 (0.96 - 2.28)	0.08
Hispanic	1,022 (22.5)	219 (23.1)	1.11 (0.93 - 1.33)	0.26	0.89 (0.68 - 1.15)	0.37
White	2,119 (46.7)	409 (43.1)	Reference		Reference
Other	76 (1.7)	12 (1.3)	0.82 (0.44 - 1.52)	0.52	0.86 (0.44 - 1.67)	0.66
Language
Spanish	444 (9.8)	121 (12.8)	1.36 (1.09 - 1.68)	0.006	1.31 (0.95 - 1.80)	0.10
English	4,008 (88.3)	806 (84.9)	Reference		Reference
Other	89 (2.0)	22 (2.3)	1.23 (0.77 - 1.97)	0.39	1.21 (0.71 - 2.07)	0.48
Indication
Screening	2,060 (45.4)	322 (33.9)	1.12 (0.85 - 1.47)	0.43	3.66 (2.42 - 5.54)	< 0.001
Maternal age	1,190 (26.2)	364 (38.4)	2.19 (1.66 - 2.89)	< 0.001	2.46 (1.73 - 3.50)	< 0.001
Screen positive	398 (8.8)	76 (8.0)	1.37 (0.96 - 1.94)	0.08	1.83 (1.24 - 2.72)	0.002
Fetal anomaly	501 (11.0)	70 (7.4)	Reference		Reference
Other	392 (8.6)	117 (12.3)	2.14 (1.54 - 2.95)	< 0.001	2.10 (1.47 - 3.00)	< 0.001

Table 2. Unadjusted and Adjusted Predictors of Fragile X Carrier Screening

Not tested (N = 4,541) (%)

Tested (N = 949) (%)

Unadjusted OR (95% CI)

P-value

Adjusted aOR* (95% CI)

P-value

*Controlled for all predictors and covariates.

Gestational age at visit

< 16 weeks

3,715 (81.8)

799 (84.2)

1.18 (0.98 - 1.43)

0.08

1.53 (1.21 - 1.95)

< 0.001

≥ 16 weeks

826 (18.2)

150 (15.8)

Reference

Insurance type

Medical/Medicaid

1,145 (25.3)

317 (33.5)

1.49 (1.28 - 1.73)

< 0.001

1.96 (1.61 - 2.39)

< 0.001

Private

3,382 (74.7)

630 (66.5)

Reference

Family history

Fragile X

149 (3.3)

73 (7.7)

2.90 (2.17 - 3.89)

< 0.001

2.06 (1.48 - 2.86)

< 0.001

Inheritable

231 (5.1)

79 (8.3)

2.03 (1.55 - 2.65)

< 0.001

1.44 (1.06 - 1.96)

0.02

Multifactorial

381 (8.4)

159 (16.8)

2.47 (2.02 - 3.03)

< 0.001

1.88 (1.47 - 2.40)

< 0.001

Non-contributory

3,780 (83.2)

638 (67.2)

Reference

Counselor

409 (9.2)

210 (22.2)

14.04 (9.60 - 20.54)

< 0.001

12.63 (8.54 - 18.67)

< 0.001

1,064 (23.8)

323 (34.1)

8.30 (5.77 - 11.95)

< 0.001

7.88 (5.42 - 11.47)

< 0.001

403 (9.0)

98 (10.3)

6.65 (4.43 - 9.99)

< 0.001

5.62 (3.69 - 8.56)

< 0.001

349 (7.8)

76 (8.0)

5.96 (3.90 - 9.09)

< 0.001

5.48 (3.55 - 8.48)

< 0.001

404 (9.1)

73 (7.7)

4.94 (3.24 - 7.55)

< 0.001

4.55 (2.94 - 7.05)

< 0.001

808 (18.1)

120 (12.7)

4.06 (2.74 - 6.01)

< 0.001

3.48 (2.32 - 5.22)

< 0.001

95 (2.1)

13 (1.4)

3.74 (1.91 - 7.34)

< 0.001

3.46 (1.72 - 6.97)

< 0.001

930 (20.8)

34 (3.6)

Reference

Counseling time

≥ 60 min

1,071 (23.6)

325 (34.2)

2.24 (1.89 - 2.66)

< 0.001

2.87 (2.04 - 4.02)

< 0.001

> 30 - 60 min

781 (17.2)

251 (26.4)

2.37 (1.97 - 2.85)

< 0.001

2.55 (1.80 - 3.61)

< 0.001

> 5 - 30 min

363 (8.0)

58 (6.1)

1.18 (0.87 - 1.59)

0.28

1.66 (1.10 - 2.52)

0.02

≤ 5 min

2,326 (51.2)

315 (33.2)

Reference

Invasive procedure

Yes

431 (9.5)

218 (23.0)

2.84 (2.37 - 3.41)

< 0.001

2.46 (1.98 - 3.06)

< 0.001

4,110 (90.5)

731 (77.0)

Reference

Maternal age

≥ 35 years

1,542 (34.0)

441 (46.5)

1.69 (1.47 - 1.95)

< 0.001

0.97 (0.75 - 1.25)

0.83

< 35 years

2,999 (66.0)

508 (53.5)

Reference

Ethnicity/ancestry

Ashkenazi Jewish

137 (3.0)

59 (6.2)

2.23 (1.62 - 3.08)

< 0.001

1.38 (0.96 - 1.97)

0.08

African American

297 (6.5)

57 (6.0)

0.99 (0.73 - 1.35)

0.97

0.95 (0.68 - 1.32)

0.75

Asian

762 (16.8)

160 (16.9)

1.09 (0.89 - 1.33)

0.41

1.07 (0.86 - 1.34)

0.53

Asian Indian

128 (2.8)

33 (3.5)

1.34 (0.90 - 1.99)

0.15

1.48 (0.96 - 2.28)

0.08

Hispanic

1,022 (22.5)

219 (23.1)

1.11 (0.93 - 1.33)

0.26

0.89 (0.68 - 1.15)

0.37

White

2,119 (46.7)

409 (43.1)

Reference

Other

76 (1.7)

12 (1.3)

0.82 (0.44 - 1.52)

0.52

0.86 (0.44 - 1.67)

0.66

Language

Spanish

444 (9.8)

121 (12.8)

1.36 (1.09 - 1.68)

0.006

1.31 (0.95 - 1.80)

0.10

English

4,008 (88.3)

806 (84.9)

Reference

Other

89 (2.0)

22 (2.3)

1.23 (0.77 - 1.97)

0.39

1.21 (0.71 - 2.07)

0.48

Indication

Screening

2,060 (45.4)

322 (33.9)

1.12 (0.85 - 1.47)

0.43

3.66 (2.42 - 5.54)

< 0.001

Maternal age

1,190 (26.2)

364 (38.4)

2.19 (1.66 - 2.89)

< 0.001

2.46 (1.73 - 3.50)

< 0.001

Screen positive

398 (8.8)

76 (8.0)

1.37 (0.96 - 1.94)

0.08

1.83 (1.24 - 2.72)

0.002

Fetal anomaly

501 (11.0)

70 (7.4)

Reference

Other

392 (8.6)

117 (12.3)

2.14 (1.54 - 2.95)

< 0.001

2.10 (1.47 - 3.00)

< 0.001